After a weekend of searching for baking soda in Vienna, I am aware of the following facts: what we call sodium (or natrium) bicarbonate, NaHCO3, could also be called sodium hydrogencarbonate, sodium bicarb, bread soda, cooking soda, bicarb soda, saleratus or bicarbonate of soda. Or, even, E500. In Austria, Natron. You go figure.

Anyway, if you happen to find it, here a project you could use it for: